Rotary electrical switch



Dec. 15, 1953 D. w. SNOW ROTARY ELECTRICAL SWITCH 2 Sheets-Sheet 1 FiledMay 2, 1952 IN VEN TOR. DA 4 5 14 fiA OM/ ATfZQ/Vfy N O W Y I R m 2 M mM 9 m a MS w 7 e 2 h M W W 6 IV A n0 s L 2 M C e l M f 0 1L Y B D. W.SNOW ROTARY ELECTRICAL SWITCH Dec. 15, 1953 Flled May 2 1952 PatentedDec. 15, 1953 ROTARY ELECTRICAL SWITCH Dale W. Snow, Seattle, Wash.,assignor to Boeing Airplane Company, Seattle, Wash., a corporation ofDelaware Application May 2, 1952, Serial No. 285,735

1 Claim. 1

This invention relates to an electrical current conducting device andmore particularly to a plural circuit connecting member that may be usedas a rotary switch or a commutator.

The invention comprises the molded plastic assembly of multipleconducting, spacing and insulating segments around a common shaft. Theassembly is rotatably mounted with brushes contacting the conductingsegments distributing current from and to the respective circuits.

The purpose of the invention is to provide a plural circuit connectingmember which is lightweight, compact and dependable.

It is an object of the invention to provide a plural circuit connectingmember readily manufactured at a reasonable cost.

It is an object of the invention to provide a. plural circuit connectingmember adaptable to varying switching requirements over a wide range ofregular and irregular timing sequences.

The purpose and objects of the invention will become more apparent asthe following description is read with reference to the drawings Whereinthe same part is identified by a like numeral throughout the views. Inthe drawings:

Figure 1 is a perspective view of the plural circuit connecting memberand brushes.

Figure 2 is a perspective view of the components of the circuit memberin Figure 1 prior to being molded in plastic.

Figure 3 is a perspective view of a portion of the components in Figure2 comprising a switching unit before assembly.

Figure 4 is a side view of the switching segment incorporated in theembodiment shown in Figures 1, 2 and 3.

Figure 5 is a side view of a modified switching segment.

Figure 6 is a side view of another modified switching segment.

As shown in Figure 1, the invention is a cylindrical switch orcommutator [0, with conducting segments I I and slip rings l2 arrangedin a spaced relationship to contact respective brushes 13. The segmentsH and the rings l2 form part of the surface of the cylinder 10 whichprimarily appears as a molded plastic form on a central shaft 14. Themolded plastic serves the dual function of insulating and holdingtogether the conducting components of the circuit connecting member l0.

Figure 2 shows the assembly of the component parts prior to theirincorporation within the molded plastic and Figure 3 illustrates aportion of these parts before assembly. The part I5 is an insulatingsleeve for placement over the shaft [4 to insulate it from the multipleswitching units l6 mounted side by side on the shaft [4. Each of theunits is composed of the following parts: a switching segment H, aconducting spacer l1 adjacent to the segment II, a slip ring 12 on theopposite side of the spacer l1, and an insulating spacer II to insulatethe switching unit 16 from an adjacent unit.

During the molding step in the manufacture of the switch I0, all theparts shown in Figure 2 are covered completely with plastic. The holes I9 in the slip ring insure the proper plastic bonding of the insulatingspacer I8 to the slip ring l2. After the molding, a turning operation isemployed to acquire the desired diameter of the switch I0. Subsequentlygrooves 20 are cut through the outer plastic surface to expose theconductors and to establish guides for the contact brushes I3.

The overall design of the plural circuit connecting member I0 isadaptable to irregular switching requirements. A selected number ofmultiple units [6 are arranged side by side and each unit [6 isespecially adapted to transmit current following a specific timingsequence. The switching segments have contact surfaces of differentlengths arranged at variable intervals along the circumferential path.

Three illustrative types are presented in Figures, 4, 5 and 6. Theswitching segment ll of Figure 4 has a contact surface which completes acircuit through one brush during one short period of a single shaftrevolution. The switching segment [9 of Figure 5 has a contact surfacewhich completes a ircuit during one half the period of each shaftrevolution. The switching segment 2| of Figure 6 intermittinglycompletes a circuit eight times through one brush during one shaftrevolution.

Other sequences and durations of electrical impulses can be acquired byfurther modifications (not shown) such as providing multiple contactingsurfaces of different arcuate dimensions on the respective switchingsegments and providing multiple take off brushes around the individualswitching segments.

The direct mounting of some of the conducting members to the shaft whichis at ground potential makes the rotary switch or commutator suitablefor opening and closing ground circuits at different intervals and forvariable periods.

Having now particularly described and ascertained the nature of the saidinvention and in 10 Number body molded around the slip ring, switchingsegment, and conducting spacer, with grooves formed in the plastic toguide brushes that contact the slip ring and switching segment as the 5switching device rotates.

DALE W. SNOW.

References Cited in the file of this patent UNITED STATES PATENTS NameDate 2,277,899 Aufiero Mar. 31, 1942

